1. Technical Field
The present invention relates to a liquid ejecting apparatus, such as an ink jet printer, equipped with liquid ejecting heads that cause pressure fluctuation to occur in pressure chambers communicating with nozzles so as to eject a liquid within the pressure chambers from the nozzles.
2. Related Art
A liquid ejecting apparatus generally includes liquid ejecting heads that can eject a liquid as liquid droplets, and can eject various kinds of liquids from the liquid ejecting heads. A representative example of a liquid ejecting apparatus is an image recording apparatus, such as an ink jet recording apparatus (printer) that has ink jet recording heads (referred to as “recording heads” hereinafter) and that performs recording by ejecting liquid ink as ink droplets from nozzles of the recording heads. In recent years, liquid ejecting apparatuses are not limited to image recording apparatuses, but are also applied to various types of manufacturing apparatuses, such as display manufacturing apparatuses. Recording heads for an image recording apparatus are configured to eject liquid ink. Colorant ejecting heads for a display manufacturing apparatus are configured to eject red (R), green (G), and blue (B) colorant solutions. Electrode-material ejecting heads for an electrode manufacturing apparatus are configured to eject a liquid electrode material. Bioorganic ejecting heads for a chip manufacturing apparatus are configured to eject a bioorganic solution.
With regard to such printers in recent years, improvements in ink ejection properties are demanded so as to allow for higher image quality. In particular, the ink ejection properties (e.g., the amount and the traveling speed of ink ejected from the nozzles) sometimes vary among the recording heads due to a production variation in the recording heads. For this reason, after the production of each recording head, a two-dimensional code including an optimal parameter value, such as a drive voltage, required for generating a drive signal for driving a pressure generator of the recording head is bonded to the recording head. After the recording head is attached to the printer body, the value of the two-dimensional code is read, and the value is written into a built-in nonvolatile memory in the printer. When the printer performs ejecting operation, a drive signal is generated on the basis of the optimal value written in the nonvolatile memory. JP-A-2002-337348 proposes an example of such a printer. Accordingly, optimal ink ejection properties can be obtained for each recording head, thereby providing a printer with high image quality.
A single head unit having multiple recording heads that are arranged in and fixed to a head fixing member, such as a sub carriage, is known. Regarding a printer equipped with such a head unit, in a state where the head unit is accommodated in an outer shell member, such as a casing, it is sometimes difficult to individually read the two-dimensional codes of the recording heads, as compared with a case where there is only one recording head. For example, in the case where the recording heads are arranged adjacent to each other in the scanning direction, if the two-dimensional codes are bonded to surfaces of the recording heads that are parallel to the scanning direction, the two-dimensional code of one recording head cannot be read because the recording head is blocked by the adjacent recording heads. If the two-dimensional codes are bonded to surfaces (front surfaces or rear surfaces) of the recording heads that are perpendicular to the scanning direction, it is difficult to read the two-dimensional codes since the recording heads are blocked by the frame of the printer or the aforementioned outer shell member.